The proposed Statistic and Data Management Core for the Program Project will provide the computational and analytic resources for successful data collection, storage, linkage, and analysis for all the projects in the Program Project. The proposed core will have both a data management component and a statistical analysis component. The goals of the data management protion of the core include: 1) development of direct computer entry programs for the neuropathobiology data, 2) facilitation of transmission of computer- generated laboratory results, and 3) establishment and maintenance of a data base library linking all projects. The statistical responsibilities of the core will include providing design advice and statistical programming, and providing methodologic expertise on specific questions arising from the use of longitudinal studies with multiple measures of cognitive impairment. The research goals of this Program Project present complexities and challenges both in the management and in the analysis of the data. First, data management will be complicated because of the large quantity of data in varied formats from separate sites, the longitudinal nature of the styd designs and the need to link data from multiple times of observation and multiple studies within the core. The analysis of longitudinal data requires sophisticated methodology to characterize patterns of change in each person, to model similarities and differences across groups of people, and to look for associations between change in one measure and change in another or between clinical change and post-mortem neuropathobiologic findings. This core will provide expert support from a statistical research team experienced in the conduct of longitudinal studies.